Gustav hoffmann



No. 624,49L

No Model.)

LII.Y

Patented May 9, |899. E. G. HGFFMANN.

DEVICE FDR FEEDING WIRE.

(Application led Mar. 5, 1898.)

2 sheets-sheet l.'

@d @f Wm.

, No. 624,49I. Patentedk May 9, |1899.

E. G. HOFFMANN.

DEVICE FOR FEDING WIRE.

(Application led Mar. 5, 1898.)

2 Sheets-Sheet 2.

(No Modal.)

VWM/5555.

THE NoRms PETERS ce., FHoTu-Llmc.. wASNlNaToN, D, c.

on the wire.

NrTED STATES PATENT Oruicn.

ERNST GUSTAV HOFFMANN, OF LONDON, ENGLAND.

DEVICE FOR FEEDING WIRE.

SPECIFICATION forming part of Letters Patent No. 624,491, dated May 9, 1899.

Application filed March 5, 1898. Serial No. 672,754. ,(No model.)

To 'all whom it may concern.'

Be it known that I, ERNST GUs'rAv HOFF- MANN, a subject of the German Emperor, residing at London, England, have invented a certain new and useful Improvement in Devices for Feeding W'ire, of which the following is a specification.

VThis invention relates to certain improvements in devices for feeding wire adapted for ball-cutting, screw-making, screw or nail heading, and like machines, the object of the invention being to provide devices which will feed the wire positively a regulated distance each time without slip when a high reciprocating speed is employed and which will yield when excessive pressure is brought to bear upon the parts by reason of inaccuracy in the diameter of the wire.

In carrying out the invention it has been specially designed in connection with a ballmaking machine in which the wire fed to the machine is gripped and which is released at intervals, the balls being shaped from the rotating wire by means of cutters presented to it. For the purpose of illustration,therefore, the invention will be described with reference to its application to such a machine.

In the accompanying drawings, Figure l is a central vertical section through the clutch and feed-lever, a part being in elevation. Fig. 2 is a front elevation of same. Fig. 3 is a side elevation of the clutch, showing same closed Fig. 4 is a similar View showing the clutch open on the wire. Fig. 5 is a detail showing in side elevation the segments which hold the wire and a collar in section for gripping same. Fig. 6 is a side elevation of the segments alone. Fig. 7 is an end elevation with the parts opened out. Fig. 8 is a plan, looking from beneath, of the feed-lever and clutch; and Fig. 9 is a side elevation of same.

The part proper which holds the wire consists of three independent segment-jaws b b b, which are preferably first formed in one piece and then separated byv slitting with a saw. The interior diameter of these jaws is made in accordance with the wire which has to be gripped, while 4the exterior d is slightly tapered and lits into an internally-tapered collar c. Within the clutch-segments are turned some small grooves d, Figs. 5, 6, and 7, in each Y lar c.

of which is a separated ring of thin springwire. These springs act to force the segments Z9 b b apart and away from the wiref. On the outside of the clutch-segments and located about the middle of same is another groove e, in which is also a separated ring of thin spring-wire, the object of which is merely to keep the segments b b b together when they are removed from the collar c, so that the handling of the segments by themselves does not entail the separation of the parts and the falling out of the small internal springs.

Upon the collar c is mounted a housing g, having a flange g', said housing being closed at one end by a nut h, screwed therein and at the other end by an inwardly-projecting ange h', against which abuts a flange c ofthe col- Between the flange c' and the nut h. is a row of balls forming a ball-bearing. The flange g of the housing g is gripped by lugs 1I i', rotatably held by a screw j in the yokearm of a feed-lever A, such arrangement enabling the lugs it" to turn slightly when the lever is shifted, so that no twisting strain is put upon the clutch.

It will be seen that between the flanges 7L and c' there is a common rubbing contact during the rotation of the collar c with the wire when `the clutch is moved in that direction to strip the collar c from the segments, While in the other direction there is a rolling contact, this side being that which has to stand the greatest pressure or that exerted by the closing of the clutch. The opposite side may, however, be provided with aball-bearing, if deemed necessary.

The operation of the feed-clutch ,can best be followed at Figs. 3 and 4. In Fig. 3 the clutch is shown closed, which means that the functions of the machine have forced collar c through the medium of the feed-lever A and ball-bearing upon segments b. In this position the feed-clutch is ready to effect the forward motion or feed` ofthe wire whenever called upon to do so.` Fig. 4 shows this forward motion or feed of the wire having taken place and the collar driven partly off the ta-` pered segments, and therefore entirely free to revolve or to move longitudinally upon the wire by reason of springs (l, which immediately separate the segments l) b b as soon as the collar c iswithdrawn sufficiently to per-V lthe segments away from the wire and pressed against the internal walls of collar c. Therefore when the clutch has reached the position as shown in Fig. 4 and the functions of the machine call for 'the return of clutch to the position shown at Fig. 3 it can be done without any fear of the segments b l) l) sticking on the wire f, and in consequence collar c being forced upon them before the clutch reaches the extreme position to the left shown at Fig. 3. As soon, however, as the clutch does reach the above position and cannot go any farther by reason ofthe fixed part B then the collar c, being still further pushed by the actuating mechanism, is forced upon the segments as far as is required to effectually secure them upon the wire, so that collar c will not come off them merely bythe effort exerted upon it to move the wire forward or feed it; but the stripping of collar c off the segments can only be effected when the latter are in the position as shown in Fig. 4 and cannot go any farther by reason of the fixed part C they abut against, so that the actuating mech-A anism pushes collar c yet somewhat farther in order to strip it and leaving the parts in the position shown in said figure, and so the operation is repeated.

Since the closing of clutch in the position shown in Fig. 3 has to be effected when the wire is running, because in the meantime certain cutting operations are performed upon the wire, it is most important to reduce the friction between the stationary and revolving parts employed in transmitting the longitudinal motion to the clutch. It is for this reason that the ball-bearing has been inserted within the housing surrounding collar c and on that side of the housing where the greatest pressure is encountered-namely, when closing or compressing the clutch upon the w1re.

` The two fiats shown at 7c, Fig. 2, are for l the purpose of turning the nut hin the housing l The feed-lever A is operated by a cam, and thus would force the lever to assu me thesame position each time irrespective of lthe varying thickness ofl the wire, with the-result of straining the lever in the case ofthe wire being slightly larger in diameter. In order to ei'ectually overcome this difficulty, yet producethe same gripping power on the feedclutch,even should the wire Vary considerably in diameter, the feed-lever A is formed in two when setting the machine. The member F, f urtherm ore,carries a roller n, upon which the cam provided for this purpose on the machine acts. The end of lever F bears upon a stud o, carried in a recess q of the lever E, said stud being kept outwardly pressed by a springp. A pin o', thrust through the stud outside of the recess, retains the stud in place. The lever F is also provided with a recess containing aspriugs, which exerts force against a bar forming a connection across the ends of lever E. When the cam forces the lever to the right, it imparts the reverse motion to the other end, which carries the feed-clutch, and this movement produces the closing action of the feed-clutch on the wire. The said feedclutch is forced with its one end against the fixed point B, and as soon as it reaches the same-and is forced to stop there the lever, continuing its motion, closes the clutch, as by forcing the collar c uponvit until a certain compression of the members of the clutch upon the wire is reached. As soon as this happens the spring-stud o is acted upon by the end of member F to such an extent as has been determined upon by the setting of the cam, which acts upon roller fn. As will be noticed, this spring-stud o is situated a considerable distance from the fulcrum of member F, whereas point n is situated very close to said fulcrum, which is at m. Therefore a considerable transmission of power is effected. In' one form of machine, for instance, the spring-stud will begin yielding only when a pressure of from one hundred and fifty to two hundred pounds has been exerted at n, Which has been found ample to sufficiently close the feed-clutch. It will be seen that as soon as feed-clutch has reached point B and the collar has been driven as hard upon the segments as the resistance of the spring-stud permits the spring-stud Will begin to yield, thereby preventing any excessive further pressure being brought upon the collar of the clutch or any excessive strain being created in the combined levers E F by the force of the cam acting upon roller n. It will furthermore be seen that a considerable margin of movement is now obtained in the Whole lever, although the cam is in a fixed position on the one end and point Bis a fixed stop on the other end. It is therefore easy to so adjust the cam that each time the feed-clutch is gripping on the wire the spring-stud will be compressed more orless, this action depending entirely upon the wire being above or below its normal diameter. From the' moment the spring-stud is yielding it is evident that the pressure which forces the collar upon the segment is practically constant, as it will only increase slightlyin proportion to theresistance of thespring, increasing as it is being pressed home.

So far the action of the lever in connection -with the feed-clutch is explained as above only as far as it refers to the closing ofthe feed-clutch upon the wire. Now I shall proceed to describe the other part of the function of this feed-lever-namely, the stripping of the feedclutch off the Wire.

Assuming that the lever and feed-clutch be in the position that the ends ot' the segments b touch point B, and assuming that the general functions of the machine require the feeding of the wire to take place, then the cam will act upon roller n, forcingit to the left, and thereby forcing the other end of the combined lever with the feed-clutch to the right until point C is reached by the other ends of the segments, when the feeding' of the wire will be effected as far as the wire itself is concern'ed. The statement previously made as to the difiiculty caused by the varying diameter of the wire as far as it refers to the closing of the clutch on the wire is to a certain extent applicable also to thestripping of the feed-clutch upon the wire. It is clear that if collar c by virtue of the varying diameter ofthe wire occupies different positions on the Atapered segments the right-hand end of such segments could not be brought home'to point C, as is most important they should be. In order to effect perfect regularity and. reliability ot' this function of the feed, lthe spring s is provided. Said spring s is a weak one compared to the spring p and has for its object to keep the right-hand end of the segments and point C in positive touch with one anotherprior to the collarbeing stripped from the segments. It is important for the purpose of obtaining the greatest accuracy that as soon as the feed of the wire has taken place and these points are in touch with one another they remain so, because at the interval when the functions of the machine call for the feeding of the wire all clutches or other holding devices which hold the wire when in operation are open, and therefore the Wire is perfectly free to be displaced from its true position by concussions,vibrations, &c. Following the movement of the combined levers it will be noticed thatas soon as these points are in touch and While the cam is still forcing roller n to the left the spring s will begin tooperate, allowing for a sufficient margin of movement, although the cam is in a.

fixed position and point C is in a iixed position, so that the collar c will be aptl to take dierent positions upon the tapered segments b, according to whether the wire is above or below its normal diameter. It is easy to see that the cam can be so adjusted as to provide a sufficient excess of movement so as tocompensate for the varying positions longitudinally of the collar c. The functions of the cam provide that the right-hand end of the segments and point c be kept in close touch, but Without force except by that exerted by the pressure of spring s, until a certain movement has been effected in the machine, and therefore the wire is locked in its longitudinal position, and immediately after thatthe roller n, which movement, however, is in excess of the .movement to member F, as pro vided at point s, and therefore the combined members E and F act at once as if they were one solid body, and hence the full pressure exerted at n to the left is brought to bear at the otherend tothe right, causing by positive force collar c to be stripped as far as is necessary off the segments. This last movement being effected, the cycle of operations can then again begin.

l. In a device for feeding wire a series of segments having their interior faces adapted to lit on the wire, grooves in said interior faces, springs in said grooves adapted to keep said segments out of holding contact with the wire, a groove in the outer surfaces of the segments, a spring in such groove adapted to hold the segments loosely together and means for closing said segments on the wire.

2.- Ina device forfeeding wire a series of segments having their interior faces adapted housing for the balls, and means carried by the housing for forming an abutment for the balls on the other side.

3. In a device for feeding wire a series of segments having exterior tapered surfaces for gripping the wire, a collar having an interior' surface adapted to tit on the tapered surfaces of the segments aseries of balls around said collar means for carrying and supporting same thereon, and means for forcing the collar onto the tapered segments, and withdrawing same, such balls acting as a rolling bearing between such means and a fixed part of the collar during the forcing operation.

4. In a device for feeding wire, a series of segments having their interior faces adapted to fit on the Wire and their `exterior faces ta pered, a collar having an interior tapered surface corresponding to the tapered surfaces of the segments, a flange carried by the collar a row of balls next to said flange, also carried by the collar, a housing inclosing said balls and flange, means carried by the housing for holding the collar in one position longitudinally, and a nut also carried by the collar against which the balls abut and adapted to prevent the collar moving in the other` direction longitudinally, and means for moving the housingand collar on the segments.

5. In aidevicev for feeding wire, a clutch adapted to grip the Wire, a pivoted lever for carrying same, a part pivoted to such lever, means for operating such part, and a spring interposed between the free end of such part and the lever,such spring adapted to allow the lever and its pivoted part to act together but to yield when an excess pressure is brought to bear upon the operated part.

G. In a device for feeding wire, a clutch IOO IIO

adapted to grip the wire, a pivoted lever for carrying same, a part pivoted to such lever, means for operating such part, a spring interposed between the free end of such part and the lever, and a second spring also interposed between the parts at a point nearer the pivotal point of vsame, said springs adapted to allow ythe lever and its operated part to act as a whole under norm-al conditions, but to yield in either direction of its operation under strain.

7. In a device for feeding wire, a clutch adapted to `,rrip the Wire, a pivoted lever for carrying same, a second lever pivoted about rone end of same, means for operating such second lever, a spring-stud carried by the first lever on which the free end of the second lever is adapted to press, and a spring interposed between the two levers atapoint nearer the pivotal point-of same, substantially as described.

In testimony whereof I have hereunto set my hand in the presence o-i" two subscribing witnesses.

ERNST GUSTAV HOFFMANN.

Witnesses:

ALLEN PARRY JONES, FRED C. HARRIS. 

